We still do not know what caused this week’s German train crash in Bavaria, in which 10 people died. The trains collided head-on on a stretch of single line track, but safety precautions introduced after another fatal accident in 2011 should have made this impossible.
As a German train approaches a red signal, an alarm is supposed to go off in the driver’s cab, and if he fails to stop, the brakes are supposed to go on automatically. Since the crash, there has been speculation that a signal controller may have turned off the automatic system, or even that someone else may have sabotaged it.
Rail crashes have often provided the spur for safety innovations. So in 1989, five people were killed at Purley in South London when one train ran into the back of another after going through a red light, even though the driver’s cab was fitted with an alarm that sounded when the train was approaching the danger signal.
After that, a system called ATP (Automatic Train Protection) was introduced to apply the brakes automatically if the driver ignored a red light. But that did not prevent a crash between a passenger and a goods train at Southall in West London in 1997 (see picture) in which seven people died. Neither the alarm system nor the ATP were working. For more, see London's Disasters.